Grinding machine



Oct. 8, 1929. H, H, YERK ET AL 1,730,551

'GRINDING MwHINE 0er.. s, 1929.

H. H. YERK Er AL. 1,730,551

GRINDING MACHINE y 6 Sheets-Sheet 2 Filed April 8, 1927 Inl/en ions. v/L/ ff.

Him-ne Oct. 8, 1929. H. H. YERK; ET AL GRINDING MACHINE Filed April 8, 192'? 6 Sheets-Sheet In wafers w3 WLVlIILwLm u v M Oct. 8, 1929. H, H YERK ET AL 1,730,551

GRINDING MACHINE Filed April 8. 1927 6 Sheets-Sheet 4 67 .138 139 /%7venor5.

Oct. s, 1929. H, H, YERk ET AL 1,730,551

GRINDING MACHINE Filed April 8, 1927 6 Sheets-Sheet 5 Atior'ney.

Oct. 8, 1929. y||, H, YERK ET AL 1,730,551

l GRINDING MACHINE Filed April 8, 1927 6 Sheets-Sheet 6 Patented @et 8, 1929 lllslTEl STATES HEME H. YERK. l-1D WILLIAM 5. IBAMBERGER, OF DAVENPORT, EFJ, ASSGNORS TO MICRO MACHEN C-MBANY, F BETTENDGRF, IOWA, A CGBYORATON JF OWA GRINDNG MACHNE Application filed April 8, 1927.

This invention relates to grinding machines and more particularly to portable maportable grinding machine which may be readily and rigidly disposed in grinding position adjacent a locomotive Wheel.

A further object ot this invention is to provide a grinding machine having improved adjustable elevating means whereby the machine may be readilyv and accurately positioned with respect to the surface to be ground.

Another object oit the invention is to provide a portable Grinding machine capable of rapidly Orinding relatively large cylindrical surfaces. l

A further object of this invention is to provide a locomotive crank pin grinding inachine of new and novel construction having improved combinations of parts. @ther objects or" the invention will be apparent to those skilled in the art trom the de fription ot it hereinafter given and the annexed drawings.

In the drawings:

Figure l is a perspective view ot the grindmachine disposed in cooperative relation W'th a crank pin and locomotive Wheel;y

Fi la is a fragmentary side elevation ,how ng the locomotive Wheel crank pin illusi einFigl; v

ig'. 2 is another perspective view of the rinding mechanism taken from one side iereot; i

at F

Fig. 3 is a tront elevation ot centering means tor'use with the machine;

Fig. l is a longitudinal section on hne l--i ot 3;

Serial No. 182,073.

Fig. Fig. 2;

Fig. 8 is a horizontal section taken through e grinding machine carriage on line 8-.-8 of F ig. 2; n

Fig. 9 is a longitudinal section through the upper portion or the grinding machine;

Fig. 'l0 is a transverse vertical section taken. on line lO--lO of Fig. 9; l

'll is a transverse vertical section taken on line ll-ll ot Fig. 9;

l2 is a horizontal section taken on line 12-12 ot Fig. 9; p

Fig. l isv transverse view partly in sectien taken on line 153-13 of Fig. 9; and

Fig. let is a longitudinal section through the grinding Wheel spindle, taken on line 14e-14. oit Fig. 13.

My improved grinding machine comprises generally a trame l carrying the Wheels 2 and vertically adjustable j aclrs 3 and. Mounted on the trame l is a transversely adjustable base 5. In turn, there is mounted on the base 5 a carriage 6 reciprocable longitudinally of said base. Carried by the carriage 6 is a rotatable annular headsto-ck 7 which carries a rotatable grinding Wheel spindle 8 and grinding Wheel 9. A motor l() mounted on the carriage 6 supplies power to rotate tile headstock 7 and grinding Wheel spindle 8 and to reciprocate or oscillate thevcarriage 6 longitudinally ot the base 5.

*rl-flic traine l (Figs. l, 2, 5 and 6) is shown as being substantially triangular in shape, having the sides ll, l2 and i3. To the sides ll and l2 are secured the bearing portions 14 which carry the transversely disposed axle 15 and Wheels 2. fit the junction ot the Jtraine sides ll and l2 is secure@ the swivelable caster 16. [i similar caster l? is shovvn secured to the iront side'lfl ot the trame substantially midway between the jacks 3. The Wheels 2 and casters. 16 and 17 are used to transport the grinding machine from one place to another and to dispose the machine adjacent the Work to` be ground.

cSituated adjacent the corners ot the trame l are the jacks 3 and 4- which may be adjusted vertically individually or simultaneously. The said yjacks are movable ver- 7 is a horizontal section on line 7 7 of tically in the bearing portions 13 and 19 and are substantially cylindrical in character. rl`he jacks 3 and 4 are shaped along the major portion of their length to form racls 20. Below each rackv is a threaded portiony2l arranged to cooperate with a corresponding internally threaded pedestal 22. By means of the threaded portion 2l and pedestals 22, each ack may be independently vadjusted vertically. Extending upwardly from the frame l are the caps 23, each arranged to Venclose the upper portion of a ack.

All the jacks 3 and 4 may be simultaneously moved vertically by suitable means. Thus, adjacent the forward end of the machine (Fig. 5) is a shaft 24 disposed parallel to the axle l5 and supported adjacent its ends by suitable bearing portions 25. rIhe shaft 24 is rotatable and carries pinions 26 arranged to cooperate with the rack portions 2O of the jacks 3. Extending longitudinally of the machine is a shaft 27 rotatably supported on suitable bearing portions 23 and 29 in Athe frame l, the shaft 27 having lreyed to its forward end abevel gear 30 arranged to cooperate with a correspondingbevel gear 3l keyed to the shaft 24e. Adjacent the rearward end of the shaft 27 is keyed a pinion 32 arranged to cooperate with the rack 20 of 'the rearward jacl; l. Rearwardly of the pinion 32 there is keyed to the shaft 27 a worin wheel 33 cooperatively associated with a transversely disposed worm 34, the said worm being carried by a transverse shaft 35 which l may be turned manually by a suitable c-ranl;

36 as shown in Fig. 2. By turning the crank 36, therefore, the three j aclrs 3 and l may be raised or lowered simultaneously, whereby to raise or lower the entire grinding mechanism.

Referring to Fig. 7 the ends of the shaft 2li are preferably rotatably mounted in suitable bearings, such as the frictionless bearings 37. XWhen the frame l has been raised to the desired vertical position, moreover, further vertical movement may be prevented by suitable locking means between the frame and each of the jacks, such, for example., as shown in enlarged form in Fig. 7. Thus, the keyed interiorly threaded sleeves 33 and 39 are di. posed in the aperture 40, the set screws il etrtending into the keyways of the sleeves 33 and 39 to prevent rotation thereof. The bolt 42 having the spaced, oppositely threaded portions Li3 and le extends int-o the sleeves 33 and 39. The bolt l2 is prevented from longitudinal movement by the set screw l5 engaging the bolt Ll2 between the threaded portions 43. and lit. Upon suitably tur the bolt 42, therefore, the sleeves 33 and Ymay be drawn together to engage the jack 3 tightly to prevent vertical movement thereof, and vice versa. Locking means similar to that shown in 7 for the aclis 3 and acl: i are indicated at Li6 and i7 respectively.

0n the upper surface of the frame l are mounted a plurality of pairs of slideways 49, and 5l, and 52, upon which slideways the base 5 rests. .lournaled in the portion forming the slideway 5l is a shaft 53 threaded at its inner end and shaped at its outer end to cooperate with a suitable crank 5a. The threaded portion ofthe shaft 53 is arranged to cooperate with the interiorly threaded block 56 carried l y and secured to the base 5. By turning tl e iandle 5er, therefore, the base 5may be adjusted transversely of the frame l. Vllhe base 5 may be secured in any transverse position of adjustment by bolts 57 and nuts 53, said bolts extending upwardly from the undercut grooves 59 in the slideways i9 and 52 through the bosses 60 of the base 5.

At the forward end of the frame l is an upwardly extending portion 6l having a top leway surface and undercut transverse groove 63, and having a front slideway comprising the surfaces 6d and undercut groove [in adjustable grinding wheel dressing tool 66 is arranged to cooperate with the groove 63 and thus be adjustable transverselyV of the slideway surface 62. A member 67 i s. 5, 6 and 3) having a vertical machined surface 63 is arranged to slide in the groove (S5 and along the front slideway surface 64, the said member 67 being adapted to cooperate with a nnichinedv surface 69 (Fig. l) of a locomotive wheel. 7() as will be more fully explained hereinafter. Extending transversely of the frame l and journaled in the upstanding member 61 is a rod or bar 7l, hools72 adjustable longitudinally of the frame l being' secured to the ends of said bar, said hooks being arranged to cooperate with the chains 73 for maintaining the grinding machine in rigid position adjacent the locomotive wheel as will more fully appear hereinafter.

The base 5 (Fig. 9) is shown as provided with the transverse end portions 74 and 75 and with the intermediate' transverse channel-shaped portion 76. Carried by the end portion 75 and intermediate portion 76 is a longitudinally extending section 77 shaped to form a rack groove 73. Secured to the intermediate transverse section 76 is the block 56 (Figs. 9 and l0) provided withY an inter nally threaded aperture ing the threaded portion 55 of the shaft 53. The block 56 is shown as provided with the sleeves 79 overlying the threaded portion of the shaft 53.

lisposed in the groove or slideway 73 is the rack 3() which is maintained within the groove 73 by suitable bearing blocks 3l secured to the section 76. Adjacentits rearward end, the rack 30 carries an upwardly extending stub shaft 32 which will be more fully described hereinafter in connection with the longitudinal reciprocation of the carriage 6 from the motor l0.

lhen the carriage 6 is to be reeiprocated by the motor 10, the raclr 30 is locked against longitudinal movement, but when the carriage 6 is to be reciprocated manually the rack is permitted to move freely in the slideway 78. The rack 80 may be locked against longitudinal movement by suitable means such as shown in Figs. 9 and 11, wherein is shown a bolt 88 extending transversely of the base 5 adjacent the section 76. The bolt 88 has a flanged orhooked end 84 arranged to engage one side of the rack 80 and to cause said rack to engage tightly with one sideof the slideway 78, as indicated in Fig. 11. The bolt83 may be held in tightly cooperative relation with the rack 80 by a nut 85 cooperating with the exterior of the base 5.

Means are provided for manually moving the rack 80 longitudinally. Thus, referring particularly to Figs. 9 and 10, a shaft 86 is journaled in the longitudinal base portion 77 and the wall 87 ofthe base5. To the shaft 86r adj acent the portion 77v is keyed a pinion 88 engageable with the rack 80. Also keyed. on the shaft 86 adjacent the wall 87 is an inl ternal gear 89 engageable with the pinion 90 carried by the shaft 91 which is journaled in the boss 92 and which extends outwardly therebeyond. The shaft 91 is suitably shaped at its outer end to cooperate with manual turning' means, such as a crank. By rotating the shaft 91, therefore, the rack 80 can be readily moved longitudinally inthe groove 78, and carriage 6 moved longitudinally of the base 5.

Slidable longitudinally on the slideways 98 of the base 5 is the carriage 6. The carriage 6 may preferably engage each slideway 93 on a plurality of surfaces, as indicated in Fig. 10. Suitable adjustable gibs 94 may, of course, be provided to take up wear. At the forward end of the carriage 6 are the bearing portions 95 and 96 arranged to enclose and support the hollow annular rotatable headstock 7. The headstock 7 is preferably pro-` vided with a gear 97 for rotation of the headstock. Journaled in the headstock 7 is the spindle housing' 98 which may be rotatably adjusted manually or automatically by means to be described. Eceentrically journaled in the spindle housing 98 is the grinding wheel spindle 8 which is preferably mounted in frictionless bearings. vThe spindle 8 is arranged to be continuously rotated at a rela-y tively high speed during the operation of the machine.

At its forward end, the grinding wheel spindle 8 carries a grinding wheel 9 which is preferably relatively wide and which preferably comprises a plurality of relatively narrow spaced cylindrical wheel portions. The advantages of this form of .grinding wheel will appear hereinafter. It will be understood, of course, that relatively narrow grinding wheels may also be employed` with my machine without departing from the invention. A suitable grinding wheel yguard 99 may partially enclose the periphery of the grinding wheely 9. At its-rearward end the spindle 8 carries a driving pulley 100 are rangedto receive power from the motor 10.

At the rearward end of the carriage, and

mounted on the removable top portion 101,

is the electric motor 10 arranged to receive electric power from any suitable source of supply. Directly beneath the cover or top 101 is a compartment 102 containing power transmission mechanism, and arranged to contain lubricant so that the mechanism therein may be partially or completely submerged in said lubricant. y I

Mechanism is carried by the carriage 6 for rotating the headstock 7 and simultaneously reciprocating the carriage 6 longitudinally of the base 5, during the rotation of the grinding wheel spindle 8. rThus, referring particularly to Figs. 8 and 9, mounted, preferably in frictionless bearings, in the sleeve 103A, which sleeve is in turn ournaled in the bearing portion 108, is the longitudinally extending shaft 104 which carries at its forward end a pulley 105 engaged in driving relation wit-h the puls ley 106 on themotor drive shaft 107 by the belt 108. At its rearward end the shaft 104 carries a bevel gear 109 which meshes with the bevel gear 110 disposed intermediate the ends of the stepped collar 111 and keyed thereto. The collar 111 is rotatably mounted on the transverse shaft 112 and is provided with clutch teeth 111A. The shaft 112 which is shown as shouldered at 112A is mounted in frictionless bearings 113 and 1181-1 carried by the non-rotatable sleeves 182 and 188 journaled in the side walls of the carriage 6. The shaft 112 also carries the worm 114. To maintain the gear 110 in engagement with the gear 109 a sleeve 184 is disposed on the shaft 112 intermediate the collar 111 and the adjacent frictionless bearing 113. A bearing washer 185 may be disposed intermediate the collar portion 111 and sleeve 184. Bushings 186 and 1.87 may be disposed intermediate the shaft 112 and the stepped collar portions 111B and 111C respectively. 1t will thus be seen that the collar 111 is fixed against longitudinal movement on the shaft 112l by the sleeve 184 and shoulder 112A whereby the gear 110 is maintained in` engagement with the gear 109. It will be understood, however, that any suitable means may be employed to retain the gears 109 and 110 in operative relation.

Intermediate the bevel gear 110 and worm 114 is a clutch collar 115 operated by the clutch arm 188, shaft 116 and clutch lever 117 pivoted at 118. The shaft 116 is journaled in the portions 189 and 190. rllhe clut-ch collar 115 is keyed to and slidable on the shaft 112, the said collar 115 having teeth 115A engageable with the teeth 111A of the gear collar 111 to cause the shaft 112 to rotate with the gear 110. The clutch collar 115 is shown as carrying a sleeve 115B arranged to overlie the teeth 111A and 115A. j

Below t-he transverse shaft 112 and extending longitudinally of the carriage 6 is the shaft 119 ournaled at 120 and 121 in frictionless bearings. Directly beneath theworm 114 vis the worm wheel 122 keyed to the longitudinal shaft 119, the worm 114 and worm wheel 122 being disposed in driving relation. At the forward end of the shaft 119 is keyed a gear 123 (Figs. 8 and 10) which gear is disposed in cooperative relation to the gear 97 carried by the headstock 7.

Referring particularly to Figs. 8, 9 and 10, it will be seen that the headstock 7 may be rotated from the motor 10, the power being successively transmitted to the pulleys 106, 105, gears 109 and 110, worm 114, worm wheel 122, gear 123, to the gear 97 on the headstock 7. lfhe rotation of the headstock can be stopped or started by manipulation of the clutch collar 115 by the clutch lever 11'4 as previously described.

The carriage 6 may also be reciprocatcd longitudinally of the base 5 simultaneously with the rotation of the headstoclr 7. Thus, rearwardly of the worm wheel 122, the longitudinal shaft 119 (Figs. 8 and 9) carries the worm 124 which cooperates with the horizontally disposed worm wheel 125 keyed to the vertical shaft 126 journaled in the bearing portion 127. Keyed to the lower portion of the vertical shaft 126 below the chamber 102 is the cam member 128 having a cam groove 129 (Figs. 9 and 12) On the previously inentioned stub shaft 82 of the rack 80 is mounted around a bushing 82A a cam roller 130 whichchine is preferably so adjusted that the forward edge of the grinding wheel is disposed adjacent the shoulder of the crank pin portion being ground (Fig. 1a) when the carriage is in forward position. The carriage preferably remains stationary in forward position while the headstock maires an uneven number of revolutions, such as one and a fraction revolutions. rThe object of the uneven number of revolutions is to prevent the formation of scallops or patterns on the finished ground surface and to insure uniform even grinding of the surface of the pin adjacent a shoulder thereof. After the said stationary period, the carriage moves to rearward position, forwardly again, and the aboved-mentioned operation repeated.

l' lhen the rack 80 (Figs. 9 and 11) is free is released, rotation of the cam 128 (Fig. 9) will cause such longitudinal movement of the rack, and the carriage 6 will remain stationary. When, however, the rack is fixed against longitudinal movement, rotation of the cam 128 will cause longitudinal movement or reciprocation of the carriage 6 on the base 5. 1n causing reciprocation of the carriage 6 on the base 5 by power from the motor 10, it will be seen that the power is successively transmitted through the pulleys 106 and 105, bevel gears 109 and 110, worm 1.14, worm wheel 122, worm 124, worm wheel 125, and cam 128.

rlhe headstock 'a' may also be rotated by manual means. Thus, the transverse shaft 131, journaled in the sleeve 183, may be rotated by a crank handle 132. 'The inner end of the shaft 131 is provided with a projection 133 arranged to engage with a corresponding detent in the adjacent end of the shaft 112 whereby to retate said shaft 112. The shaft 131 may be maintained in, or out of, operative engagement with the shaft 112 by suitable means, such as the balll 191 carried in the slot 192 and cooperative with either of the circumferential grooves 193 and 194 in the shaft 131. vBy rotation of the shaft 131, the headstoclr 7 may be rotated to a desired position, as indicated in the previous description relating to the rotation of the headstoclr 7 from the motor 10. From Fig. 8 it will be seen that when the shaft 131 is moved inwardly into engagement with the shaft 112, the collar 195 on the shaft 131 engages the clutch lever 117 to disengage the clutch collar115 from the collar V111. Conversely, when the lever 117 is operated to engage the clutch collar 115 with the collar 111, the shaft 131 is moved out of operative engagement with the shaft 112. TWhen it is not desired to have the carriage 6 reciprocate simultaneously with the manual rotation of the headstock 7, the bolt 83 may be loosened torelieve the rack 80 from lixed engagement lwith the base 5.

r`he grinding wheel spindle 8 may be rotated from the motor 10 at any adjusted position of the spindle housing 98, and moreover, the spindle housing 98 may be manually adto move longitudinally, as when the bolt 83 justed or automatically adjusted during the i rotation of the spindle 8 and headstoclr 7. r1`hus, referring particularly to Figs. 13 and 14, a worm wheel 134 is mounted on the spindle housing 98 adjacent the rearward endv thereof. The worm wheel 134 engages with the worm Y135 keyed to the shaft 136 journaled in the bracket 137, The shaft 136 may be manually rotated by a crank 138 associated with the suitably shaped outer end of the shaft 136. rlhe spindle housing 98 may, by thus rotating the shaft 136, be rotated manually to the desired position and the grinding wheel spindle 8 disposed at a desired distance from the aXis of the headstock 7.

Suitable pulleys are provided whereby the spindle 8 may be continuously rotated at any adjusted position of the spindle housing 98. rl'hus, a pulley 189 is secured to the for-V ward end of the drive shaft of the motor 149. hiounted on the rearward side of the headstock 7 is a fixed idler pulley 140, and fixed pivotally to the headstock 7 is a crank 141 pivoted on the pin 14.2, the crank 141 carrying a movable idler pulley 148 at the outer end of one crank arm 144. The other crank arm 145 is adjustably secured to a resilient member or spring 146 secured to the headstock 7. A belt 148 may be suitably associated with the pulleys 100, 189, 140 and 148 as indicated in Fig. 18. The spring 146 is arranged to position the pulley 148 to maintain the belt in tightdriving relation at any adyjusted position of the spindle housing 98.

Automatic means for rotating the'spindle housing 98 to thus automatically feed the grinding wheel 9 tothe work to be ground. is shown in Fig. 18. Thus, one ofthe stops 149 or 150011 the bearing portion 95 may be disposed to trip the arm 151 on every revolution of the headstock to thereby rotate toa desired degree the ratchet 152 mounted on the shaft 158. The rotation of the ratchet 152 causes the worin wheel 154 on the shaft 186 to be rotated by a worm (not shown) mounted on the shaft y158 above the ratchet 152 and beneathV the nut 155.

Means (Figs. 8, 4 and 9) are provided whereby the aXisof the headstock 7 may be disposed in longitudinal alignment with the axis of the crank pin 156 which is shown as having the shouldered cylindrical portions 157, 158, and 159. Thus the spider 169 is shown as having a pair of-Xed arms 161 and 162 and an arm 168,the arm 168 being provided with the slidable adjusting means 164 whereby the portion 165 may be brought into or out of engagement with the headstock 7. Each of the arms 161 and 162 and the portion 165 are provided with recesses 166 arranged to engage with the correspondingly shaped surface 167 of the headstock 7. Slidably journaled in the bearing portion 168 is the centering pin 169 having an outwardly tapered portion 170 arranged to engage in a conical centering recess 171 inthe crank pin 156. The centering pin 169 is preferably also provided with an adjustable hooked pin 178 arranged to cooperate with a surface, such as the surface 159 of the crank pin to provide positive means for accurately disposing the grinding machine in aligned position with the crank pin axis. Since the crank pin portion 159 is subjected to negligible wear, the hooked pin178 affords accurate means for aligning the grinding machine. The pin 178 may of course be arranged to cooperate with any of the cylindrical surfaces of the eran'r pin 156.

In cases where the portion 159 of crank pin is threaded, the centering may be accomplished entirely by the'centering pin 169. 1t

will thus be seen that, by means of the centering pin 169 or the scribing pin 178, the grinding machine may be aligned with the aXis of the crank pin.

A cover plate 197 may be secured to the rear side of the headstock 7 to cover the .aperture in the headstock whereby to prevent dust from passing through the headstock and getting into the mecl anism rearwardly of the headstock. Annular plates 198 and 199 also may be secured on the forward side of the headstock to the bearing portions 95 and 96, and gear 97, respectively, to exclude dust or the like fromthe gear97 and associated parts.

My improved grinding machine is particularly advantageous for grinding the crank pins of locomotive wheelssuch as when said wheels are disposed in upright position as on a track. The wheel shown in Fig. 1 is provided with a machined surface 69 according to the usual construction.

1n operation the grinding machine is moved adjacent a wheel 70 with the surface 68 of the slidable member 67 directly adjacent the machined surface 69 of the wheel. An ordinary machinists square may then be employed to determine the perpendicularity of the top surface 62 to lthe machined surface 69 of the wheel.. 'llo dispose the machined surface 69 at right angles to the surface 62, the jacks may ybe individually raised or lowered by means of the pedestals 22. The jacks 8 and 4 may then beV simultaneously raised by the crank 86 sufficiently for the weight of the machine to be carried by the acks 8y and 4 rather than by the wheels 2 and casters 16. The chains 78 may be disposed around certain spokes to assist in holding the grinding machine in rigid position. The centering spider 160 being in position in the headstock 7, the machine may be raised by means of the crank 86until the axis of the headstock 7 is in approximate alignment with the axis of the crank pin 156. The pin 169 may then be rotated to determine by means of the hook 178 the exact position of alignment of the headstock 7 with the crank pin 156. The chains 78 may then be tightened by adjusting the nuts 174 to hold `the grinding machine rigidly adjacent the wheel 70. The carriage 6 may then be inanf ually reciprocated by turning the shaft 91 to dispose the grinding wheel 9 adjacent the particular' surface to be ground, and the nut 85 tightened so that the carriage 6 may be reciprocated from the motor 10 during the AOrindine operation. The spindle housing 98 mav be suitably adjusted by turning the crank 188 accordingl to the diameter of the portion oA pin to be ground. The spider 160 is then removed before the grinding operation is commenced. The motor 10 is started and. the clntcl'i collar '115 disposed. in.

"rati-ve nasi4 Cil tion by moving the clutch lever 117, Wherebv the grinding Wheel spindle 8 is rotated, the headstoclr 7 simultaneously rotated, and the carriage 6 simultaneously reciprocated longitudinalh7 of the base 5.

1t will be noted that the crank pin being ground may extend into the annular head-` stoclr 7 thus permitting the grinding` of relative long crank pins. Moreover, the headstoelr 7 may be counteinveighted, if desired, as at 200, to counterbalance the Weight of the grinding Wheel and spindle and housing 98.V

It Will also be seen that the drive shaft 107 of the mot-or 10 is in longitudinal alignment With the aXis of the headstock 7, Whereby smooth uniform rotation of the grinding Wheel spindle S may be most readily obtained.

As was previously noted, the character of longitudinal movement of the carriage is dependent upon the shape of the cam 128. Variations in the length of reciprocative movement and in the intermittent reciproeation of the carriage may be varied by substituting a different cam 128. Itk may be noted that the gear ratio of the gears rotating the headstock, and the mechanism reciprocating the headstock are so calculated preferably that the headstoch malres one and a fraction revolutions for one complete reciprocationfof the carriage. In this manner patterns or scallops in the ground surface are prevented and a smoother finish obtained.

It will thus be seen that vvehave provided a portable grinding machine of advantageous characteristics for grinding crank pins and the lilre of locomotive or other Wheels.

Our improved machine is readily adjustable and rigid in adjusted position and arranged to grind Work with extreme accuracy.

It will moreover be noted that We have provided a grinding Wheel which is relatively Wide whereby to provide a. large grinding surface and whereby but very small reciprocative movement Vof the carriage is necessary to grind a relatively large cylindrical surface. The grinding Wheel may, of course, be integral or may comprise a plurality of relatively thin cylindrical discs which are preferably spaced.

Furthermore, it is to be understood that the particular forms of apparatus shown and described, and the particular procedure set forth, are presented for purposes of explanation and illustration and that various modifications of said apparatus and procedure can be made Without departing from our invention as defined in the appended claims.

l.Vhat We claim is:

1. In a portable grinding machine for grinding locomotive crankpins and the like, in combination, a frame, means associated with said frame to adjust said frame vertically, a base adjustable transversely of said frame, a carriage movable longitudinally of said base, a rotatable annular headstock mounted on said carriage, a rotatable grinding Wheel spindle ournaled in said headstoelr, a motor carried by said carriage, driving means driven by said motor whereby to simultaneously rotate said grinding Wheel spindle, rotate said hcadstock and reciprocate said carriage longitudinally of said base.

2. In a portable cranlr pin grinding machine, in combination, a frame mounted on Wheels, means associated With said frame to adjust said frame vertically, a base adjustable on said frame, a carriage mounted on said base and movable longitudinally thereof, a rotatable headstoelr mounted on said carriage, a spindle housing journaled in said headstock, a grinding Wheel spindle eccentrically journaled in said spindle housing, a motor mounted'on said carriage, means for manually moving said carriage longitudinally of said base, means for manually rotatingksaid headstoelr, means for rotating said grinding Wheel spindle directly from the shaft of said motor, and means driven from said motor for rotating said headstockand reciprocating said carriage simultaneously With the rotation of said spindle.

3. In a portable grinding machine having a base, a carriage movable longitudinally of said base, a rotatable annular headstoek mounted on said carriage, and a rotatable grin ding Wheel spindle carried by said headstoclr, in combination, a motor, gears driven from said motor, a shaftA carrying a Worm', a clutch disposed between said aforementioned gears and said Worm, a shaft carrying a Worm Wheel engageable With said aforen'ientioned Worm, said shaft carrying another Worm, a third shaft carrying a Worm Wheel engageable with said aforementioned Worin and carrying a cam having a cam groove, a, rackv Vico gitudinally of said base, said base being shaped to form alongitudinally extending groove, a rack longitudinally movable in said groove, means for securing said rack against longitudinal movement, a cam roller carried by said rack, a hollow cam carried by said carriage, said roller engaging in cooperative relation with said cam, manually operable means for longitudinally moving said rack when said rack is freely movable whereby to move said carriage to a desired position, and means for rotating said cam when said rack is secured against longitudinal movement, Whereby to reciprocate said carriage longitudinally of said base.

5. In a portable grinding machine, in combination, a base, Va carriage movable longitudinally of said base, ashaft carried by said carriage, a gear arranged to transmit power to said shaft, a clutch interposed between said gear and said shaft to operatively connect or disconnect said gear with or from said shaft, headstock rotating mechanism operable by rotation of said shaft, means arranged` to engage said shaft whereby said shaft, and consequently said headstock, may be manually rotated, and means to automatically operate -said clutch to disconnect said gear from said shaft when said manual shaft rotating means is brought into operative relation with said shaft.

6. In a portable grinding machine for grinding locomotive wheel crank pins and the like, in combination, a supporting frame arranged to be disposed on a iioor adjacent the work, a carriage reciprocable longitudinally of said frame and the surface to be ground, a rotatable headstock carried by said carriage, a grinding wheel carried by said headstock, said headstock being revoluble exteriorly of the work to grind an external cylindrical surface thereon, and adjustable means carried by said frame for raising and lowering said carriage to dispose said headstock in desired position relative to the work to be ground.

7. In a portable grinding machine for grinding a horizontal crank pin on an upstanding locomotive wheel having a vertical machined surface, in combination, a supporting frame arranged to be disposed on a floor adjacent said locomotive wheel, said frame having a machined surface arranged to abut said locomotive wheel machined surface, a carriage carried by said frame, a rotatable grinding wheel spindle carried by said carriage revoluble exteriorly of said crank pin to grind an eX- ternal cylindrical surface thereon, means carried by said frame for adjusting portions of said frame vertically to dispose said grinding wheel spindle with the axis of orbital movement thereof in a horizontal plane and to dispose said frame machined surface in vertical position whereby said frame machined surface may abut said locomotive wheel machined surface, and means carried by said grinding machine to adjust said carriage vertically and laterally whereby said grinding wheel spindle may be disposed with the axis of orbitali'novement thereof in exact longitudinal alignment with the axis of the surface to be ground on said crank pin and whereby said crank pin may be provided with a cylindrical ground surface disposed in exact hori- Zontal position.

8. In a portable grinding machine for grinding locomotive wheel crank pins and the like, in combination, a supporting frame arranged to be disposed on a floor adjacent the work, a carriage carried by said-frame, a rotatable headstock carried by said carriage, a rotatable grinding wheel carried by said headstock and revoluble exteriorly of the work to grind an external cylindrical surface thereon, means carried by said grinding machine for adjusting the posit-ion thereof relative to said work, and means carried by said headstock arranged to extend forwardly thereof toward said work to cooperate with said work whereby said machine may be readily disposed with the axis of orbital movement of said grinding wheel spindle in longitudinal alignment with the axis of the cylindrical surface to be ground in said work.

In testimony whereof we ama our signatures.

WILLIAM J. BAUMBERGER. HENRY H. YERK.

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